Foreign substances may be generated within a display panel during an existing cell-assembling process of a liquid crystal display (LCD). In case where the foreign substance has a size which is not sufficient to cause a significant variation in a panel gap value of the display panel, the display panel will pass the cell test as a good product but will be detected as a defective product during the module test when the foreign substance exerts an external force onto the display panel to crush a metal wire at a thin film transistor (TFT) side or to conduct an Indium Tin Oxide (ITO) electrode at the TFT side with an ITO electrode at a color filter (CF) side within the display panel, which may result in waste of materials.